The notation a_n+1 represents the next term in a sequence, where n is an index that indicates the position of a term. For example, if a_n is the current term, a_n+1 is the term that follows it. This notation is commonly used in mathematics, particularly in sequences and series. In a sequence, each term is generated based on a specific rule or formula. For instance, in the arithmetic sequence defined by a_n = a_1 + (n-1)d , d is the common difference. Here, a_n+1 can be calculated as a_n + d , illustrating how each term builds upon the previous one.